Combined motor and clutch



3 Sheetns-Sheet l 7, 1954 J. A. MAsoN ETAL COMBINED MoToR AND cLu'rcH Original Filed Dec.

Dec. 7, 1954 J. A MASON ETALl Re. 23,902

COMBINED MOTOR AND CLUTCH Original Filed DGO. 13, 1951 3 Sheets-Sheet 2 QObev-t' C. rolepILrL v-(b @6MM/fur# Lp Dec. 7, 1954 v J, A. MASON ETAL Re. 23,902V

' COMBINED uo'roR AND CLUTCH original Filed Dec. 13, 11;51 :s sheets-sheet s 45 @VCMAM'IPW uw? Cjvronroexf se. 23.902 Reissues nec. 7,

l 23;02 `coMinNnnMorroii AND .ci-.Uren

JamesvA. Mason, Worcester, Mam., and Robert C. Kraeplin, Beloit, .Wll., to :WarneruElectrie Brake di Clutch Company. South Beloit, Ill.,4 n corporation of No. 261,474, December `:13, :19.51. Application :for'

reime September `$16, 31954, Serial No. .456,897

zlicnims. {oasis-416) Matter enclosed in Ileavyshrackeiszl] yappears in 'the `or'lgiitial patent but forms v)no `part of this reissue Vspecilicatiolj f tter rprinted hl Italics indicates ltlleaddltioiis made `by reksne.

This invention vrelates -to an `electric `motor `incorporating therein one or more electromagnetic ffriction `devices shaft `of `the motor. t

One object `is to incorporate two magnetic friction de vices, one a clutch and the other a-brake.' -within an elecfor applyinga driving or .retarding ytorque fto the output tric :motor housing without increasing thestandard axial nl length of the latter.

Another object is to utilize the magnetic parts of the motor stator and rotor (to form `.part o the magnetic tlux vcircuit of a magneticfriction device .disposed between the rotor and one'end beli of ftliemotor housing.

.they driving and driven elements of the .clutch and `the brake in axially spaced A further object is to arrange relation between the rotor and end bell and Aextend the flux .circuits of both devices through ztlie iron of. the bell and through a tubular projection extending inwardly therefrom.

Still another objcctis to extend the magneticux circuits for the brake and clutch through a common magnetic member while at the same `time insuring proper dis`- sipation of the residual magnetic flux following deenergiration of either one of the devices.

A further .object is to provide freedom of axial ltloating yofthe driving and driven clutch parts while mounting the latter rigid with the rotor and motor shaft.

The invention also resides in the novel arrangement of the parts of the friction .devices to promote overall axialcompactness, to take up wear at the friction surfaces automatically, to eliminate stray ilux` circuits, and to simplify the construction ,asa whole.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with ythe accompanying drawings, in which Fi re 1 is an elevational view of an electric motor of stan ard design incorporating a clutch and brake arranged in accordance with the present invention, one end portion of the motor housing being broken away and shown in section. Y

. Fig. 2 is a section taken onthe line 2-2 of Fig. l.

Fig. 3 is an enlarged fragmentary diametrica'l sectional view through one end portion of the motor. 1

Fig. 4 is a view similar to Fig. 3 showing a modified form of the invention.

Fig. 5 is an electrical and ux circuit diagram.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail the preferred embodiment. It is to be understood, however, that we do not intend to limit the invention by such disclosure but aim to `cover all modifications and alternative constructions `:falling within the spirit and scope of the invern tion as expressed in the appended claims.

In thedrawings, the invention is shown incorporated in an electric induction type motor of conventional design and dimensions comprising a squirrel cage rotor 5 and a laminated stator core 6 carrying windings 7 and supported in a housing 8 enclosing one end of the motor shaft 9 which projects from theoppos'ite end of the housing with the-part tovbe driven; The

rotor ilsllifimlnated ano. arrlies inducto bars 10 and vend rings orming ya squirre cage win ing.

Usually, the :laminationsof the "stator core are `held between vflangeson a ring 1-2 pressed into the central cylindrical portion `13 ofthe housiing 8. The windings "7 whichJencircle the-stator poles project axially and out* wardly fromthe stator andthus necessitate spacing fof the housing end 'bells l14 and 15a substantial distance `from :the gend of the rotor. 'Fan 4blades .20a projecting from one `en dof `the rotor induce `ailow -of axially :through vthe statorparts. c

Ihelinnertopen lends f :the `bells y14 and `15 are telescoped at 16 ywith the fend of the housing cylinder.13 ,and the ythree .parts are clamped .together by the usual tie 'bolts "17. The bell 14 -enclo'ses vn reduced portion r18 yof the motor shaft which is journaled in 'a `bearing v19 ing of the .above character of an electromagnetic friction clutch 21 for disengagea'bly coupling the rotor to the shaft 9 and also a magnetic friction `brake 22 for retarding the shaft, all ofthe parts of the clutch and brake being disposed in the limited space between the rotor and one end bell and within the projecting ends `of the motor windings 7. In general, the necessary axial compactness is lachieved by .utilizing the motor housing 8 and the magnetic parts of the stator and rotor as part'- of the tlux circuit of one orboth of the two magnetic friction devices and by mounting 'the windings ofboth-fdevices in a novel manner on oneend bell, the bell l`4fin this instance.

More specifically,4 the driving element 23 of the clutchr and the non-rotatable member 24 of the brake are sp'a'c'ed4 apart axially and secured respectively to vone end of the' vrotor and the opposed end bell 14, while the drivenelement 2S of the `clutch and the rotary member 26 of the brake are disposed adjacent each other and carried""by the intervening portion of the shaft 9. This arrange# ment of the clutch and brake parts within the closed end of the motor housing is made possible by journaling the rotor 5 loosely 'on the central portion of the shaft 91 To this end, Ythe apertured rotor laminations are, inthe form shown in Fig. 3, pressed onto a sleeve 27 rotatable on the central part of the shaft 9 between shou1ders'28 by which the rotor is heldv against axial movement; The sleeve iscomposed of suitable non-magnetic bearing'i'nate-v rial such as bronze.

The driving clutch element 23 is a generally llat apertured disk of iron having an inner hub 29 secured as by countersunk cap screws 30 to the end of the staclcibf rotor laminations. -The disk thus presents a ilat'outer surface for axial gripping engagement with the opposed face of the driven clutch element 25 whose hub 31 is', 'in the formshown in Fig. 3, loosely splined on a tlutedprtion 32 of the motorshaft. Segments 33 of wear resistant friction material are set in the disk 25 ush with the magnetic face of the disk.

The friction faces of the clutch disks are drawn into gripping engagement by energization of a multiple turn annular winding 34 which causes magnetic flux to thread axially through the outer peripheral portions of the two disks. To avoid the necessity of slip rings, the winding 34 is mounted stationarily in a cylindrical recess 35 enst4 in the outer part of the dat end portion of the end :bell

14 being spaced axially from the ends of the motor .wind-r 40 is concentric with the motor shaft and closel'y`en-fcircles the driven clutch disk 25 which is widenedit't` its the clutch rings the driving clutch disk 25, axially throughv the outer.

p'ortionsof vthe'clutch faces, radiallyinwardly through the' driving disk, axially through the vflange 29 and thc rotor laminations, outwardly through the rotor 5, the gap 41, the lstator core 6 and into the housing shell 13, axially along the latter and the joint 16, and finally inwardly around the winding 34 through the outer periphery of the lend bell to the end of the axially projecting flange 39. The flux thus ,threading 'through the axial faces of the clutch elements 23 and 25 at all points around the latter, draws the faces into axial gripping engagement causing a driving torque to-be transmitted from the rotor to the shaft 9.

The brake 22 is of the same general construction as the clutch, the rotary part 26 being a duplicate of the clutch disk and loosely splined on the fiuted part 32 of the shaft between the disk 25 and the bearing 19 so that its`cylindrical periphery is similarly disposed close to the` internal surface of the projection 39. l Wear segments 42 are set in the inner part of the brake disk flush with the magnetic surface which is disposed opposite a fiat face on the stationary brake member 24. The latter is an iron disk' clamped by screws 43 against the end of a huh`44 on the end bell'14 supporting the sleeve20.

Ari vannular winding 45 smaller in vdiameter than the clutch winding is disposed between the hub 44 and the rib 3B and is yclamped by the brake disk 24 against the end wall of the bell 14. v

A magnetic flux .circuit of toroidal shape as indicated by the dot-dash outline in the upper part of Fig. 3 and at 61 (Figs. 4 and' 5) thus encircles each part of the winding 45. The circuit extends from .the tubularprojection.39 inwardly across the radial gap 46 into the periphery of the brake disk 26, axially into the disk 24 and finally outwardly. through the iron of the end bell and around the winding 45. ,When the latter is encrgized,'the disks 24 and 26 are drawn into axial grippingv engagement producing a retarding torque which is applied to the motor shaft and is of afmagnitude correspending to the degree of energization of the' winding.

By arranging the gap 46 concentricwith the clutch and brake elements 25 and 26, thewidth is not influenced by wearing off of the friction. faces in service use. Any such wear at the axial faces is taken up automatically through the loose spline mounting of the disks 25 and 26 and the provision of means for maintaining these disks in continuous but light mechanical contact with the coacting axial fixed elements 23 and 24. Herein, this meanscomprises a compression spring 47 coiled around the hubs of the disks 25 and 26 and bearing at opposite ends against the opposed sides of the disks.

In installations .where the motor is subjected to freque nt starting and stopping or sudden load changes, it is desirable to fasten the driven clutch disk 25 rigidly'to theshaft 9 as shown in Fig. 4 and mount the driving clutch element for free axial floating.. For this purpose,

the disk 25 may be bolted to a radial flange on a collar 48 abutting against a shoulder on the shaft 9 and secured to the latter by a key 49. In this modification, the rotor is supported on the shaft through end bushings 50 into which are ressed anti-friction bearings 51 whose inner race rings 2 are slidable axially along the intermediate portion of the shaft. 4As the clutch faces wear olf in service, the rotor shifts along the shaft 9 thus permitting to engage properly in response to energization of the winding 34. y

l For certain applications, it is desirable to holdthe clutch parts yieldable in light mechanical contact at least at the time when the clutch is energized. With the floating armature arrangement above described, this may be accomplished by so constructing the clutch parts and locating the shaft 9 initially that the rotor 5 of the motor will be disposed slightly off-center to the left relative to the stator as shown in Fig. 4. The rotor S tends to cen- Y ter itself in the stator when the latter is energized thus fill producing a small force which holds the driving clutch disk 23 in light mechanical contact with the disk 25 when the motor stator is energized as will always be the case when the clutch is to be engaged.

.Axial floating of the rotary brake disk 26 is achieved by supporting the latter on angularly spaced pins 53 mounted in -and projecting from the flangel of the collar 48. As before, the spring 47 holds the rotary brake disk against thestationary disk 24 thus takingzup wearatthebrake surfaces... 1.

The energization of the clutch and brake=windings 34 and 45 from a direct current source such as a battery 53 may be controlled in any suitable way as by a double throw switch 54 and, if desired, may be timed automatically with the application and interruption of current'to the motor windings 7.I When the motor is runningV with the windings 34 and 45 deenergized, the ,rotor 5 and its sup rting bushing 27 turn on the shaft 9which remains stationary until the clutch is energized. The driving clutch disk 23 turnsV with the rotor so that a torque will be ap.-

plied to the shaft when the windingi34 is energized causing, The .brakel the two disks 23 and 25 to grip each other. disk 26 turns with the shaft on which a retarding torque will be exerted when the winding 45 is energized which usually takes place `after disengagement of the clutch. The motion of the shaft and the parts driven thereby may thus be arrested quickly without the necessity of overcoming the energy of the rotating rotor.

The invention also contemplates arrangement of thev brake and clutch windings 34 and 45 and connection of the same to the current source 53 in a novel manner such,

that the magnetic flux produced byenergizing one of the windings threads the common portion 39 of theV two ux circuits 60' and 61 in a direction opposite to that ofthe ux in the other circuit when current is applied lto the other winding. This relationship is achieved by winding the coils 34 and 45 in the same direction and by connecb` ing their adjacent terminals to one4 terminal of the source 53, the other terminals being connectable to the other power lead by selective closure of the switches 54.` with these connections, the clutch ux may, as indicated.- in.v

Fig. 4, thread the circuit 60 in a counterclockwise direction, the brake liux traversing the path 61 clockwise when the winding 45 is energized. It will be observed that the directions of the flux in the common part 39 of the two circuits are opposite.

'Iheresidual magnetic flux which tends to persist inl each circuit after interruption of the current owin theA corresponding winding follows the same path and is in the same direction as the main linx. Owing, however, to the fact that the direction of the main liux incither circuit is opposite to that of the residual flux remaining after de energization of the other winding, the residual flux is' quickly neutralized instead of being augmented. As aresult, there is no tendency for the b rake to drag under the influence of residual ux when the clutch winding 34 is energized. Similarly, the clutch is completely releasedby neutralization of its residual liux when the brake winding is energized following deenergization of the clutch winding.

It will be observed that both the clutch 21 andthe brake 22 have been built into the motor housing without increasing the axial dimensions thereof and without in any way detracting from the efficiency of the motor. All of this has been achieved through the inclusion of the iron parts of the motor in the magnetic flux circuits of the clutch and brake, the use of stationary windings to avoid the necessity of slip rings, and by the novel arrangement of the clutch and brake parts in relationto the rotor, the stator windings and the end bell 14. At the same time, a minimum number of'changes in the construction of )the motor parts is required, these being in the shaft 9 and the end bell 14.

Those parts 23 and 24 of the clutch and brake which, are subject to wear and may require' replacement after bell, a magnetic tubular projection rigid with said bell and spanning the peripheries of said disks, clutch and brake windings supported by said end bell exteriorly and interiorly of said projection, an annular magnetic member secured to said bell for axial gripping engagement with said outer disk to form a friction brake and completing a magnetic ux circuit encircling each portion of said brake winding and extending successively through said bell, said member, said outer disk and said projection, and an annular magnetic element secured to the end of said rotor adapted for axial gripping engagement with said inner disk to form a friction clutch and completing a ux circuit extending around each portion of said clutch winding and successively through said element, said inner disk, said projection, said end bell, said motortcore and said rotor.

2. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing with an end bell, a shaft journaled in said bell, inner and outer magnetic disks rotatable with said shaft and disposed between said rotor and end bell, a magnetic tubular projection rigid with said bell and spanning the peripheries of said disks, clutch and brake windings supportedby said end bell exteriorly and interiorly of said projection, an annular magnetic member secured to said bell for axial gripping engagement with said outer disk to form a friction brake and complete a magnetic llux circuit encircling each portion of said brake winding and extending successively through said bell, said member, said outer disk and said projection, and an annular magnetic element on the end of said rotor adapted for axial gripping engagement with said inner disk to form a friction clutch and complete a ilux circuit extending around each portion of said clutch winding and successively through said element, said inner disk, said projection, said end bell, said motor core and said rotor.

3. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing with an end bell, `a shaft journaled in said bell, a magnetic friction clutch adjacent said rotor having an annular winding secured to said bell and having axially engageable driving and driven elements respectively secured to the end of said rotor and to said shaft, a magnetic friction brake between said clutch and said bell having an annular winding secured to said bell within said clutch winding and axially engageable elements respectively secured to said bell and said shaft, and an annular magnetic member secured to said end bell concentric with and spanning said driven clutch element and the rotatable brake element and completing a llux circuit through said [driving and driven] broke elements and end bell and around each part of said brake winding and a separate flux circuit through said bell and [brake] driving and driven elements, said stator core and said rotor and around each part of said clutch winding.

4. The combination of, an electric motor having a stator` core, a rotor, and a magnetic housing with an end bell, a shaft journaled at one end in said bell, a friction clutch having an annular winding secured to said bell and axially engageable magnetic elements one secured to said rotor and the second rotatable with said shaft, a friction brake having an annular winding secured to said bell within said clutch winding and axially engageable magnetic members one secured to said end bell and the other rotatable with said shaft adjacent said second clutch element, and a tubular magnetic projection rigid with said end bell between said coils and extending axially and inwardly across the outer periphcries of said driven clutch element and the rotatable brake member, said projection completing two ux circuits each including said end bell and `one encircling said clutch coil and extending through said magnetic elements and the gap between said stator core and said rotor the other of said flux circuits extending through said brake members.

5. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing with an end bell, a shaft journaled in said bell, a friction clutch having an annular winding secured to said bell and axially engageable magnetic elements one secured to said rotor and the second rotatable with said shaft,` a friction brake having an annular winding secured to said bell and axially engageable magnetic members one secured to said end bell and the other loosely splined on said shaft adjacent said second clutch element, and a magnetic part rigid with said end bell and encircling said driven clutch element and the rotatable brake member, said part completing two magnetic flux circuits through said end bell and said elements and members and respectively encircling each angular portion of said clutch and brake coils and one extending radially through said stator core and said rotor.

6. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing with an end bell, a shaft journaled in said bell, a friction clutch having an annular winding secured to said bell and axially `engageable magnetic elements one secured to said rotor and the second rotatable with said shaft, a friction brake having an annular winding secured to said bell and axially engageable magnetic members one secured to said end bell and the other rotatable with said shaft adjacent said second clutch element, a magnetic part rigid with said end bell and encircling said driven clutch element and the rotatable brake member, said part completing two magnetic ux circuits through said end bell and said elements and members respectively and respectively en` circling each angular portion of said clutch and brake coils and one extending radially through said stator core and saidrotor, and spring means yieldably urging said driven clutch element and said rotatable brake member apart.

7. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing with an end bell, a shaft journaled in said bell, a friction clutch having an annular winding and axially engageable magnetic elcments mounted on said rotor and said shaft respectively, a friction brake having an annular winding and axially engageable magnetic members mounted` on said end bell and said shaft respectively, and magnetic means completing magnetic ilux circuits through said end bell and said elements and members respectively and respectively encircling each section of the clutch and brake windings and one extending through the gap between said stator core and said rotor.

8. The combination of, an electric motor having a stator core, a rotor, and a magnetic housing, a shaft journaled in said housing, a friction clutch having an annular winding and axially engageable magnetic elements re'- spectively rotatable with said rotor and said shaft, a friction brake having an annular winding and axially-engageable magnetic members respectively secured to said housing and said shaft, and magnetic means completing two magnetic flux circuits through said housing andl said elements and members respectively and one extending through the gap between said stator core and said rotor.

9. The combination of, an electric motor having a stator core, a rotor, a magnetic housing with an end bell'. a shaft journaled therein, two electromagnetic friction devices axially spaced along said shaft between said rotor and said bell and having annular windings respectively energizable to couple said rotor and said shaft and to retard the latter, and magnetic means completing magnetic flux circuits around the respective windings and through magnetic parts of said housing and said friction devices, one of said flux circuits extending through the gap between said stator core and said rotor.

i0. The combination of an electric motor having a stator core with eld coils projecting axially therefrom, a rotor, and a magnetic housing with an end bell, a shaft journaled in said bell, a magnetic friction clutch axially spaced from said rotor and having an annular winding energizable to couple said rotor to said shaft, a mag-A netic friction brake having an annular winding energizable to cause a retarding torque to be applied tosaid shaft, said clutch and brake windings being concentric with each other and mounted on said end bell substantially in a common plane disposed outwardly beyond the ends of said field coils, and magnetic means completing separate flux circuits through said end bell and the magnetic parts of said clutch and brake respectively and extending around each part of each of the respective windings.

1l. The combination of, an electric motor having a housing including bells at opposite ends, a shaft journaled in said end bells, a rotor, a stator fitting in said housing and having eld windings projecting axially toward said windings, two annular magnetic windings stationarily mounted on one of said yend bells and encircling said shaft, a magnetic friction clutch having axially `engageable magnetic rings disposed within said recess and respectively rotatable with said rotor and said shaft, means providing a toroidal llux path encircling each portion of one of said windings and extending axially through said clutch rings, a magnetic friction brake comprising two magnetic rings adapted for axial gripping engagement and respectively supported on said shaft and `said one end bell, and means providing a toroidal llux path encircling each portion of the other of said windings and extending axially through said second rings.

12..'I`he combination of an electric motor having a statorcore, a rotor, and a magnetic housing with an endbell, a shaft journaled in said bell, a magnetic `friction clutch adjacent said rotor having an annular winding secured to said b ell and having axially engageable driving and driven elements respectively secured to said rotor and said shaft, and an annular magnetic member securedto said end bell concentric with 'and spanning said driven clutch element and` completing a magnetic flux circuit extending axially through said elements and the member, outwardly around said winding, and finally inwardly through said stator core and said rotor. y C

13. The combination of,` an electric 'motor having a stator core, a magnetic housing with an` end bell, a shaft journaled in said bell, and a rotor journaled on said shaft to turn relative thereto, a magnetic friction clutch adjacent said rotor having an annular winding and axially engageable driving and driven magnetic elements respectively secured to the end of said rotor and to said shaft, and magnetic means completm a magnetic linx circuit around each part of said winding and extending through said end bell, said elements, and the gap between said stator core and said rotor.

' 1,4. The combination of, an electric motor having a stator, a rotor, a magnetic housing for said stator including an end bell, a shaft journaled in said end bell and projecting axially through said rotor for free rotation relative thereto, bearings supported by said shaft and supporting said rotor for axial floating `movement relative to the shaft, an electromagnetic friction clutch v comprising'driving and driven magnetic rings respectively secured to said rotor and said shaft at one end of the rotor, and a-multiple turn winding mounted on said end bell and adapted when energized to draw said rings into axial gripping engagement, said rotor, when said clutch rings are in engagementvwith each other being disposed ol-center relative to said stator in a direction-away from said clutch whereby the tendgaged by energization of said outer coil and including a magnetic driving element adapted for axial gripping engagement with the other of saidv rings and fortuin part of a magnetic ux circuit extending axially [with through said other ring, outwardly into said flange, and then outwardly through said bell and around said outer coil.

17. The combination of, an end bell of magnetic ma terial having an annular flange projecting axially therefrom, inner and outer annular multiple turn windings mounted on said bell inside and outside of said flange, axially spaced magnetic rings tting within said ange, said bell and the adjacent one of said rings vcooperating to form a magnetic friction brake having a toroidal llux path encircling each part of said inner windin and a magnetic friction clutch including a [driven driving member of magnetic material disposed on the side of said adjacent ring remote from said bell and adapted for axial gripping engagement with said other ring, said driving member comprising part of a toroidal magnetic tlux path extending through said other ring,`

'said shaft, a cylindrical magnetic flange projecting axially from said bell and closely surrounding the peripheries of both of said rings, two annular windings mounted on said end bell inside and outside of said llange, said bell having a frictionV surface adapted for axial gripping engagement with the adjacent one ot' fill eney of said rotor to center itself in the stator when the latter is energized holds said rings in engagement with each other. f

l5. The `combination of, an electric motorl having a stator, a rotor, a magnetic housing including an end bell, a shaft journaled in said end bell andy projecting axially through said rotor for free turning relative thereto, bearings supported by said shaft and supporting said rotor foraxial floating movement relative to the shaft, an electromagnetic friction clutch comprising driving and driven magnetic rings respectively secured rigidly to said rotor rotor, and a multiple turn winding mounted on said end bell and adapted when energized to draw said rings into axial gripping engagement.

16. The combination of, a motor end bell in the form of av disk of magnetic material having an annular llange projecting axially from one side of the bell and inwardly from the outer periphery thereof, said ange having an internal cylindrical surface concentric with the axis of said bell, two axially spaced magnetic rings concentric with the axis of said disk and disposed within said flange with their peripheries disposed closely adjacent said cylindrical surface, two multiple turn al1- nular coils respectively mounted on said bell within and outside of said flange, means on said disk cooperating with the adjacent one of said rings to provide an electromagnetic friction brake having a flux circuit of toroidal form encircling the inner one of said coils and saced yextending, through said member, said bell, said flange and said shaft at one end of the v said rings to form a magnetic brake, and a driving clutch member disposed beyond the endl of said flange and adapted for axial gripping engagement with said other ring to=form a magnetic clutch, said clutch and said brake `having magnetic tlux circuits each extending axially through said llange.

19.The combination of, an end bell for a motor, a shaft journaled thereinl and projecting axially thereof. a magnetic ring rotatable with said 'shaft about the axis of-said bell and axially spaced inwardly therefrom, an vannular winding stationarily mounted on said end bell.

fai driving clutch element encircling said shaft and adapted for axial' gripping engagement with said ring to form a magnetic clutch adapted to be engaged by energizati'on of said winding, and an annular magnetic member projecting from said` bell and having an internal surface closely encircling said ring but extending short ofl said element, said member constituting part of a magnetic llux path of toroidal shape extending axially between said element and ring, outwardly into said member and then axially through said member, and finally radially outwardly around said winding and through said t bell to the outer periphery thereof.

20. The combination of, an electric motor having a housing including bells at opposite ends, ka shaft journaled in said end bells, a rotor, a stator fitting in said housing and having iield windings projecting axially toward said end bells and ovcrhanging the ends of said rotor to provide a cup shaped recess around said shaft and within the windings, an annular magnetic winding stationarily mounted on one of said end bells and encircling said shaft, a magnetic ring rotatable with said shaft and j disposed .in said recess, a driving clutch element disposed in said recess between said ring and said rotor and rotatable with said rotor, said element being adapted for axial gripping engagement with said ring, and means coacting with said one end bell and providing a toroidal llux path encircling each portion of said winding and extending axially through said ring and said element, said last mentioned means including n magnetic member projecting from said one end bell toward and into said recess.

21. The combination of, an electric motor having a housing including bells at opposite ends, a shaft journaled in said end bells, a rotor, a stator fitting in said housing and having field windings projecting axially toward said end bells and overhanging the ends of said rotor to provide n cupshaped recess around said shaft and within the windings, an annular magnetic winding stationarily mounted on one of said end bells and encircling said shaft, two magnetic rings disposed within said recess and adapted for axial gripping engagement, means coupling one of said rings to said shaft for rotation therewith, and. means coacting with said one end bell4 naled in said end bells, a rotor, a stator fitting insaid housing and having field windings projecting axially toward said end bells and overhanging the ends of said rotor to provide a cup-shaped recess around said shaft and within the windings, an annular magnetic winding encircling said shaft, magnetic rings encircling said shaft and disposed within said recess, said rings being adapted for axial gripping engagement and coacting to form a friction clutch, means coupling one of said rings to said shaft, and means providing a toroidal ux path encirL cling each portion of said winding and extending axially through portions of said rings disposed within said recess and the outer ends of said windings whereby to draw the rings into axial gripping engagement when said winding is energized, said last mentioned means including a magnetic member rigid withsaid one end bell and telescoping closely with one of said rings.

The combination of, amotor end bell of magnetic j produce magnetic llux flows in opposite directions through material having an annular ange projecting axially from one side of the bell and spaced inwardly from the outer periphery thereof, said flange having an internal cylindrical surface concentric with the axis of said bell, twoaxially spaced magnetic rings concentric with the bell axis and disposed within said flange with their peripherics disposed closely adjacent said cylindrical surface, two multiple turn annular coils of different diameters mounted on said bell Within and'outside of said flange, a member rigid with said bell and cooperating with the adjacent one of said rings to provide an electromagnetic frictionbrake havinga ilux Vcircuit of toroidal form encircling the inner one of said coils and extending throughsaid member, said bell, said flange, and said one ring, and a magnetic friction clutch engaged by ener gization of said outer coil and including a magnetic driving element adapted for axial gripping engagement with the other of said rings and forming art of a magnetic tluxk circuit extending axially [with through said other ring, outwardly. into said flange, axially along the latter, and then outwardly through said bell around said outer coilfand mechanism for energizing the brake and. clutch coils selectively to produce magnetic flux thread-` ing through'saicl ange in one direction when the clutch said flange' and along said paths when thc respective windings are energized.

25. The combination of, an end bell for a motor, a shaft journaled therein and projecting axially thereof, a pair of axially spaced magnetic rings rotatable about the axis of said bell, two annular windings of different diameters mounted on said end bell, said bell having a `friction surface adapted for axial gripping engagement with the adjacent one of said rings to form a magnetic brake adapted to be applied by energization of one `of saidwindings, a driving clutch member adapted `for axial gripping engagement with said other ring to form a magnetic clutch adapted to be engaged by energization of the other of said windings, said clutch and said brake having magnetic flux circuits encircling the respective windings and extending through said end bell and a common part encircling said rings, and means forenergizing said windings selectively to produce tiux flows in opposite directions through said common magnetic part.

26; The combination of, an end bell for a motor, a shaft journaled therein and projecting axially thereof, a pair of axially spaced magnetic rings rotatable about the axis of said bell, two annular windings mounted on said end bell, said bell having a friction surface adapted for axial gripping engagement with the adjacent one of said rings to form a magnetic brake adapted to be applied by energization of one of said windings, a driving clutch member adapted f or axial gripping engagement with said other ring` to form a magnetic clutch adapted to be engaged by energization of the other of said windings, saidclutch and said brake having magnetic iiux circuits encircling the respective windings and extending through said end bell and a common magnetic part Y encircling said rings, and meansfor energizing vsaid wind- `ings selectively to produce flux ows insaid circuits and in opposite 'directions throughv `said common magnetic t prising driving and drivenmagnetic rings respectively coil is energized and in the reverse direction during ener n' gization of said brake coil. a

24. The combination of, an end bell of magnetic material having an annular tiange projecting axially therefrom, annular multiple tum windings mounted on said bell inside and outside of said flange, axially spaced magnetic rings fitting within said ange, a magnetic member rigid with said bell and cooperating with the adjacent one of said rings, said flange, and lsaid bell 'tov form a friction brake and' a toroidal ux path encircling each part of said inner winding, a magnetic fric .parl

" by' saidl shaft andsupporting said rotor for axial tloating movement. an electromagnetic friction clutch comlsecured rigidly to said rotor and said shaft at one end of the rotor, an electromagnetic friction brake adapted when energized 'to apply a retarding torque including a lstationary ring rigid with said end bcll'and a ring adapted for axial gripping engagement with said stationary ring, and means on said [driving] driven clutch vring supporting said last mentioned brake ring for rota- `Number tion clutch including a'[driven] driving member of magnetic material disposed on the side of said ring remote from said bell andadapted for axial gripping engagement with the other of said` [other] rings, said driving member comprising part of` a toroidal magnetic ux path extending through said other ring, said flange, and outwardly through said bell around said outer winding,

and means for energizing said windings selectively to 4tion with said shaftbut for free axial floating relative thereto. f

References Cited in the (ile of this patent or the `original patent UNITED STATES PATENTS lName Date 1,665,742 Kingston Apr. 10, 1928 2,314,019 Shaw Mar. 16, 1943 2,489,365 Broussouse Nov. 29, 1949 t FOREIGN PATENTS Number Country Date 635,025 Germany Sept. 9, 1936 

